TY - JOUR
T1 - FTIR study of CO adsorption on Rh/MgO modified with Co, Ni, Fe, or CeO 2 for the catalytic partial oxidation of methane
AU - Li, Dalin
AU - Sakai, Shigemasa
AU - Nakagawa, Yoshinao
AU - Tomishige, Keiichi
PY - 2012/7/7
Y1 - 2012/7/7
N2 - The surface state of Rh/MgO catalysts modified with Co, Ni, Fe, or CeO 2 after the reduction and partial oxidation pretreatments as well as during the catalytic partial oxidation of methane has been investigated by FTIR of adsorbed CO. The results of CO adsorption on the reduced catalysts suggest the formation of Rh-M alloy on Rh-M/MgO (M = Co, Ni, Fe) and Rh particles partially covered with reduced ceria on Rh-CeO 2/MgO. The strength of CO adsorption on Rh/MgO is weakened by the modification with Co, Ni, Fe, or CeO 2. Partial oxidation pretreatment of Rh/MgO leads to a significant decrease in the CO adsorption due to the oxidation of Rh. In contrast, on partially oxidized Rh-M/MgO (M = Co, Ni, Fe) and Rh-CeO 2/MgO, the preferential oxidation of the surface M atoms or reduced ceria maintains the metallic Rh and preserves the CO adsorbed on the surface Rh atoms. The CO adsorption during the reaction of catalytic partial oxidation of methane on Rh/MgO and Rh-Ni/MgO is similar to that on the reduced catalysts. On the other hand, the CO adsorption during the reaction on Rh-Co/MgO, Rh-Fe/MgO, and Rh-CeO 2/MgO is different from that on the reduced catalysts, and this is related to the structural change of these catalysts during the reaction.
AB - The surface state of Rh/MgO catalysts modified with Co, Ni, Fe, or CeO 2 after the reduction and partial oxidation pretreatments as well as during the catalytic partial oxidation of methane has been investigated by FTIR of adsorbed CO. The results of CO adsorption on the reduced catalysts suggest the formation of Rh-M alloy on Rh-M/MgO (M = Co, Ni, Fe) and Rh particles partially covered with reduced ceria on Rh-CeO 2/MgO. The strength of CO adsorption on Rh/MgO is weakened by the modification with Co, Ni, Fe, or CeO 2. Partial oxidation pretreatment of Rh/MgO leads to a significant decrease in the CO adsorption due to the oxidation of Rh. In contrast, on partially oxidized Rh-M/MgO (M = Co, Ni, Fe) and Rh-CeO 2/MgO, the preferential oxidation of the surface M atoms or reduced ceria maintains the metallic Rh and preserves the CO adsorbed on the surface Rh atoms. The CO adsorption during the reaction of catalytic partial oxidation of methane on Rh/MgO and Rh-Ni/MgO is similar to that on the reduced catalysts. On the other hand, the CO adsorption during the reaction on Rh-Co/MgO, Rh-Fe/MgO, and Rh-CeO 2/MgO is different from that on the reduced catalysts, and this is related to the structural change of these catalysts during the reaction.
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U2 - 10.1039/c2cp41050h
DO - 10.1039/c2cp41050h
M3 - Article
AN - SCOPUS:84862301253
SN - 1463-9076
VL - 14
SP - 9204
EP - 9213
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 25
ER -